The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Generally, an exhaust gas recirculation (EGR) system is a system which is installed in a vehicle to decrease noxious exhaust gas.
This exhaust gas recirculation system reduces oxygen amount in a mixer by circulating a part of the exhaust gas discharged from the engine, reduces the amount of the exhaust gas, and reduces toxic matters in the exhaust gas.
Also, the exhaust gas discharged from the engine has high temperature, therefore the engine efficiency may be improved by utilizing the thermal energy of the exhaust gas.
Meanwhile, a fuel reformer is a device which changes fuel characteristics by using catalyst, and the fuel reformer may be applied to increase combustion efficiency or activate a post processing system.
For improvement of fuel reforming efficiency, it is important to attain sufficient activation temperature of a fuel catalyst. By the way, EGR gas has to be sufficiently heated to attain sufficient activation temperature for fuel reforming, however, it is difficult to attain activation temperature according to driving condition and supply amount of the EGR gas. We have discovered that there is a problem that reforming efficiency decreases because temperature of mixed gas decreases substantially during mixing of fuel and the EGR gas in a mixing portion of the fuel reformer.